The present invention relates to a coupling device usable in particular in circuits for transporting fluids under pressure in order to provide a quick coupling between two circuit elements such as two pipes or such as a pipe and a member that delivers or receives fluid.
Ball couplers are known comprising a male tubular endpiece having an annular external bead and a female tubular endpiece for receiving the male tubular endpiece, the endpieces being designed for being associated with respective elements of the circuit. The male endpiece is held in the female endpiece by means of balls which are pressed by locking means into abutment behind the annular bead.
In general, the locking means comprise a ball-holding cage mounted via one end on the female endpiece to extend beyond said endpiece, and a ring mounted on the holding cage to move axially between first and second positions. The ring has inside camming surfaces arranged in such a manner that when the ring is in its first position, the balls are held projecting from the inside of the holding cage so as to retain the annular bead of the male endpiece, and when the ring is in its second position, the balls are released radially and can be moved into a retracted position away from their projecting position by co-operating with the annular bead, so as to enable the annular bead to be disengaged and the male endpiece to be removed.
Such ball couplers are in widespread use in industry because of the speed with which they allow coupling to be implemented. Nevertheless, those couplers are of complex structure involving a large number of parts. As a result, as well as being heavy, the various components of the coupler are lengthy to assemble, and manufacture thereof is relatively expensive in general terms.
There also exist on the market various types of couplers that differ from one another, e.g. in terms of the length of the male endpiece or in terms of the shape of the annular bead. Thus, in some cases, in order to maintain existing circuits, it is necessary to have as many different types of coupler as there are different types installed on the circuits. Given the price of these couplers, that leads to relatively high cost for maintenance, storage, and stock management.
It would therefore be advantageous to have a coupling device that is simple in structure, easy to manufacture, and inexpensive.
For this purpose, the invention provides a device for coupling an endpiece to a member, the coupling device comprising a female portion for receiving the endpiece, a bushing mounted to slide in the female portion and possessing one end projecting from the female portion, which end is provided on the outside with at least one blocking means co-operating with the female portion to block the bushing either in a pushed-in, locking position or else in a pulled-back, unlocking position, and an opposite end provided both with front abutment means for coming into abutment with an annular bead of the endpiece, which front abutment means project radially inwards from the bushing, and rear abutment means for coming into abutment with the bead so that when the bushing is in its unlocking position, the rear abutment means are in register with a first chamber of the female portion so as to be movable by the annular abutment between a position in which they project towards the inside of the bushing and a retracted position, and when the bushing is in its locking position, the rear abutment means are received in a second chamber of the female portion having a wall that holds the rear abutment means in their projecting position.
As a result, the coupling device is simple in structure, making use of a small number of parts while nevertheless achieving coupling that is similar in effectiveness to the coupling provided by ball couplings, in particular.
In a preferred embodiment:
the rear abutment means comprise at least one deformable tab having one end secured to the bushing and an opposite end provided with a lug, the tab being deformable between a rest state in which the lug projects towards the inside of the bushing, and a deformed state in which the lug is retracted;
the front abutment means comprise at least one rigid tab having one end secured to the bushing and an opposite end provided with a shoulder projecting towards the inside of the bushing to constitute an abutment for the annular bead of the endpiece; and
the blocking means comprise at least one elastically deformable catch having one end secured to the bushing and an opposite end provided with a projection, and the female portion has an outside surface presenting at least two setbacks in axial succession for receiving said projection.
Thus, the bushing, the front and rear abutment means, and the blocking means can be made as a single piece.
Advantageously, the bushing is mounted in removable manner on the female portion.
This makes it possible to provide coupling devices in which the female portion is adapted to receive a plurality of male endpieces, and to provide interchangeable bushings each adapted to a particular type of male endpiece. Inexpensive adaptors can thus be made for connecting together two elements of a circuit corresponding to two different types of coupling device.